It can be hard to tell the difference between a 3/16" and 1/4" wrench, and it's even harder when you're underneath a car or up on a ladder. Instructables user bfk has a simple solution: just paint them different colors.

Sure, you'll end up with a toolset that looks like it was previously owned by a clown, but if you don't care what your tools look like—and why would you?—this can make grabbing the right wrench a much similar process. Bfk has not only painted his wrenches, but many of the different bolts on his car (the project he usually needs them for) so at any given moment he can just "match" the bolt to the right wrench with no problem. You could do this with anything, too, including those tiny screws on your computer. Hit the link to see more.